Table 2 Preliminary Estimate of BOD Load to Major rivers in Thailand (1986)

		(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
		DO of River	Std. DO	No. of Factory	Flow 1000 cu.m. per yr	BOD Load	70% Cost of Treatment	Treatment Residual BOD	Cost of Treatment
No.	River Name	mg/L	mg/L			tons/yr	million B	tons/yr	million B
1	Bangpakong	4		135	13,997	86,761	58.8	26,028	173.3
2	Chao Phraya	0.3	2	351	53,224	81,426	223.5	24,428	162.7
3	East Coast Gulf			123	16,345	80,427	68.6	24,128	160.7
4	Mun	3		84	7,350	75,867	30.9	22,760	151.6
5	Thachin	< 2	2	376	166,757	56,033	700.4	16,810	112.0
6	Maeklong	> 4		22	47,741	48,910	200.5	14,673	97.7
7	Ping			17	125,087	30,254	525.4	9,076	60.4
8	Nan			19	101,866	21,819	427.8	6,546	43.6
9	Chi			82	18,015	19,106	75.7	5,732	38.2
10	Khong			55	1,532	7,091	6.4	2,127	14.2
11	Prachinburi			27	281	4,618	1.2	1,385	9.2
12	Wang			13	1,517	3,719	6.4	1,116	7.4
13	Yom			5	102	296	0.4	89	0.6
14	Kok			2	18	55	0.1	16	0.1
SUM				1,311	553,832	516,382	2,326.1	154,914	1,031.7

Source: Department of Industrial Works; ONEB (1986); Department of Health (1986).

Note:	(3)	This amount of load covers only factories under motoring scheme of DIW.
	(6)	Assuming cost of treatment = 6 baht/cu.m.
	(8)	Assuming average BOD concentration = 3,000 mg/L and cost of treatment = 6 baht/cu.m.